1. Field of the Invention
The present invention is related to an apparatus for irradiating a drug with a laser beam to form ultrafine particles.
Priority is claimed on Japanese Patent Application No. 2006-135711, filed May 15, 2006, the content of which is incorporated herein by reference.
2. Description of Related Art
Some organic compounds used for medical drugs, such as anti-cancer drugs, are insoluble in water, so that they are difficult for cells to absorb. For improving the intake of the water-insoluble medical drugs by cells, it was necessary to reduce the size of the drugs to ultrafine particles which can pass through the cell membrane of the affected part. The size of ultrafine particles which can pass through a cell membrane is considered to be from 50 to 200 nm, and various apparatuses for forming such ultrafine particles have been conventionally proposed. For example, a pulverizing apparatus called a “wet ball mill” has been known. This apparatus is a cylindrical vessel having a multitude of balls made of a metal, a ceramic or a plastic accommodated therein together with a rotor having a rim ring, and is capable of pulverizing drugs by the rolling friction of the balls and the rotor.
Further, a method for forming ultrafine particles of an organic compound is known in which short pulsed laser beams of nano seconds or femto seconds are used (for example, see Japanese Unexamined Patent Application, First Publication No. 2005-238342). In this method, drugs suspended in water within a transparent vessel are externally irradiated with a pulsed laser to thereby pulverize the drugs in water.